Quantity, percentage, percentage value: Convert fractions to percentages

A percentage is actually a form of fraction, or more precisely, a fraction out of a hundred.

In other words, it is a fraction where the denominator is always 100.

Therefore, in order to convert a fraction into a percentage, we multiply it so that the denominator becomes 100.

20*5=100

15*5=75

Therefore the fraction is 75/100 and the percentage is 75%.

To convert the fraction $\frac{20}{40}$ into a percentage, we'll follow these steps:

• Step 1: Simplify the fraction $\frac{20}{40}$.
• Step 2: Convert the simplified fraction into a percentage.

Step 1: Simplifying the fraction $\frac{20}{40}$, we divide both the numerator and the denominator by their greatest common divisor, which is 20:

$\frac{20 \div 20}{40 \div 20} = \frac{1}{2}$

Step 2: To convert $\frac{1}{2}$ into a percentage, we multiply by 100:

$\frac{1}{2} \times 100 = 50\%$

Therefore, the fraction $\frac{20}{40}$ is equivalent to 50%.

To find 95% of 180, we proceed as follows:

• Step 1: Convert 95% to a decimal for calculation. That is: $95\% = \frac{95}{100} = 0.95$ .
• Step 2: Multiply this decimal by the total quantity (180): $0.95 \times 180$ .
• Step 3: Perform the multiplication: $0.95 \times 180 = 171$ .

Therefore, 95% of 180 is $171$.

To solve this problem, we will determine the number of white balls in the box using a fraction of the total number of balls.

We are given the total number of balls in the box as 18, and we know that $\frac{2}{3}$ of these balls are white. To find the number of white balls, we follow these steps:

• Step 1: Identify the total quantity, which is 18 balls.
• Step 2: Use the given fraction $\frac{2}{3}$ to find the number of white balls.
• Step 3: Multiply the total number of balls by the fraction of white balls: $18 \times \frac{2}{3}$.

Perform the calculation:

$18 \times \frac{2}{3} = 18 \times 0.6667 = 12$

Alternatively, calculate directly using fractions:

$18 \times \frac{2}{3} = \frac{18 \times 2}{3} = \frac{36}{3} = 12$

Thus, the total number of white balls in the box is 12.

Therefore, the correct answer is choice 12.